Herbicidal method employing thiadiazolyl amidines

ABSTRACT

WHEREIN R, R1, R2, R3 and Y are as hereinafter defined. Methods for using these compounds as agricultural chemicals, and formulations for pre- and post-emergent herbicidal applications are also disclosed.   This invention relates to novel amidines of the general formula:

United States Patent 1191 Cebalo et a1.

1 Apr. 1, 1975 1 HERBICIDAL METHOD EMPLOYING THIADIAZOLYL AMIDINES [73] Assignee: Air Products and Chemicals, Inc.,

Allentown, Pa.

22 Filed: on. 24, 1973 21 Appl. 190.; 409,191

Related US. Application Data [62] Division of Scr. No. 87,298, Nov. 5, 1970, Pat. No.

[52] US. Cl 71/90, 71/67, 71/73 [51] Int. Cl A0ln 9/12 [58] Field of Search 71/90, 121

[56] 1 References Cited UNITED STATES PATENTS 3,119,831 1/1964 Homer 71/121 3,260,588 7/1966 Schroeder 71/90 3,505.346 4/1970 Bcrkelhammer et a1. 71/90 3,522,267 7/1970 Duerr et al. 71/90 3.565.901 2/1971 Cebalo 71/90 3,624,088 11/1971 Benko 71/90 OTHER PUBLICATIONS Saikawa et al., Antibacterial Z-(aminoethyleneamino)5-etc.;" (1970), CA 73, No. 77289r (1970).

Primary E.\'aminer-Glennon H. Hollran Attorney, Agent, or Firm--Leroy Whitaker; Everet F. Smith [57] ABSTRACT This invention relates to novel amidines of the general formula:

wherein R, R, R R and Y are as hereinafter defined. Methods for using these compounds as agricultural chemicals, and formulations for preand postemergent herbicidal applications are also disclosed.

19 Claims, N0 Drawings HERBICIDAL METHOD EMPLOYING Tl-IIADIAZOLYL AMIDINES This is a division of application Ser. No. 87.298. filed Nov. 5, 1970 now U.S. Pat. No. 3,784,555.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to certain novel amidines and to compositions and methods for their use as agricultural chemicals 2. Description of the Prior Art Certain formamidines are known to exhibit biological activity. For example, see U.S. Pat. Nos. 3.188.316; 3,121,084. 2.853.132: 3,284.28); and 2.521.358 describing formamidines as bactericides, herbicides. fungicides. acaricides. and germicides. However. the amidines of the subject invention present novel structures unrelated to known amidines.

SUMMARY OF THE INVENTION The amidines of this invention are represented by the following general formula:

wherein Y represents oxygen or sulfur; wherein R represents a. hydrogen.

b. lower-alkyl of from 1 to 6 carbon atoms such as methyl, ethyl. propyl, i-propyl. butyl. ibutyl. s-butyl, or t-butyl. n-pentyl or n-hexyl,

c. lower-cycloalkyl of from about 3 to 6 carbon atoms. such as cyclopropyl. cylclopentyl or cyclohexyl,

d. phenyl or substituted phenyl substituted with such halo. e.g.. bromo, chloro. fluoro, iodo,

. nitro trifluoromethyl lower-alkyl of from 1 to 4 carbons, as defined above,

5. lower-alkoxy of from 1 to 4 carbons.

6. di (lower-alkyl) amino. wherein the lower alkyl groups contain 1 to 4 carbons as defined before,

7. cyano e. lower-alkenyl of up to 6 carbons atoms, such as ethenyl, 2-propenyl, l-propenyl, i-propenyl, 3-butenyl, l-methyl-Z-propenyl, l-ethylethenyl, l-butenyl, 1- pentenyl, 4-pentenyl, 3-pentenyl, Z-pentenyl, l-ethyl- 2-propenyl. l-methyl-3-butenyl, l-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, S-hexenyl, l-methyl-4-pentenyl, l-ethyl-3-butenyl. l-propyl-Z-propenyl, and any isomers of any of the foregoing,

f. substituted lower-alkyl of from 1 to 6 carbons, substituted with such as 1. halo such as bromo, chloro, fluoro or iodo; exemplary are CF3, CZFI CHFZ, (CH CF CI-I- CCI CF CCI CBr ClCI-I CH- ICH CH 2. phenyl,

3. lower-cycloalkyl of from 3 to 6 carbons such as defined before.

4. heterocyclic of from 5 to 6 ring atoms such as pyridyl or furyl.

g. halo such as fluoro. chloro or bromo h. lower-alkoxy of 1 to 4 carbons; wherein R represents a. hydrogen,

b. lower-alkyl of from 1 to 6 carbon atoms such as methyl, ethyl, propyl, i-propyl, butyl, i-butyl. s-butyl. or t-butyl, n-pentyl or n-hexyl.

c. lower-cycloalkyl of from about 3 to 6 carbon atoms, such as cyclopropyl, cyclopentyl or cyclohexyl. except that when R is lower-cycloalkyl, R is a group, as defined, other than lower-cycloalkyl,

d. substituted Iower-alkyl of from 1 to 6 carbons substituted with such as 1. halo, e.g., bromo, chloro, fluoro or iodo; exemplan)! being (CH2)2CF3, CHgCCIgCFg, CICH CH ICH CH e. Iower-alkoxy of l to 4 carbons,

f. lower-alkenyl of up to 6 carbon atoms, such as ethenyl, 2-propenyl. l-propenyl, i-propenyl. 3-butenyl. l-methyl-2-propenyl, l-ethylethenyl. l-butenyl. lpentenyl, 4-pentenyl. 3-pentenyl. 2-pentenyl. l-ethyl- 2-propcnyl. l-methyl-3-butenyl, l-hexenyl. 2-hexenyl. 3-hexenyl. 4hexenyl. 5-hexenyl. l-methyl-4-pentenyl. l-ethyl-3-butenyl, l-propyl-2-propenyl, and any isomers ofany of the foregoing; wherein R represents a. hydrogen,

b. lower-alkyl of from 1 to 6 carbon atoms such as methyl. ethyl, propyl, i-propyl. butyl. i-butyl, s-butyl, or t-butyl, n-pentyl or n-hexyl,

c. lower-cycloalkyl of from 3 to 6 carbon atoms, such as cyclopropyl, cyclopentyl 0r cyclohexyl. except that when R is lower-cycloalkyl R is a group, as defined. other than lower-cycloalkyl.

d. when R and R each represents lower-alkyl, they can be linked together through the nitrogen of the amidine group to which they are attached to form a heterocyclic ring such as piperidyl or pyrollidino; and wherein R represents a. hydrogen, or

b. lower-alkyl'of from 1 to 4 carbon atoms such as methyl, ethyl, propyl, i-propyl, butyl. i-butyl, s-butyl, or t-butyl.

DETAILED DESCRIPTION OF THE INVENTION The novel compounds of this invention can be prepared by conventional methods. For example they can be produced according to the following general equation wherein R, R R R and Y are as defined above.

Y II

amide and phosphorus oxyhalide in an inert organic solvent, such as benzene, by addition of an excess of the amide to the phosphorus oxychloride. To this mixture is then preferably added a solution of the amino compound 11. The reaction is preferably carried out under stirring and with water bath cooling. An excess of amide to amino compound is generally employed. (The amide can in some cases be used as a solvent, as well). The phosphorus oxychloride is generally employed in a slight molar excess to the amino compound. The amidine product (I) is obtained as the hydrochloride salt which can conventionally be converted to the free base, as by stirring with an aqueous solution of alkaline base such as sodium bicarbonate, sodium hydroxide and the like, followed by filtration. The compounds of this invention in their salt or free base form exhibit the desired biological activity. Thus included within the scope of this invention are the acid addition salts of the compounds of the formula I such as the hydrochloride salt, or any other acid addition salt which may be useful in formulating the compounds of this invention into useful compositions for end-use applications.

The novel compounds of the formula I thus prepared,

are useful as agricultural chemicals as they possess pronounced phytotoxic characteristics, often with surprising species selectivity, e.g., they destroy noxious weeds while valuable crops are not attacked. The novel compounds of this invention when formulated at proper dosage application levels into herbicidal compositions find usefulness in both pre-emergent and postemergent applications. In those cases where species selectivity is not exhibited these compounds find usefulness as total herbicides, at higher rates of application, because of their pronounced phytotoxic activity. Furthermore, the compounds of this invention in certain instances possess useful biological properties which render them useful as algicides, insecticides, acaricides and fungicides when formulated in conventionally appropriate pesticidal or fungicidal compositions.

Among those compounds most preferred as herbicides are those of formula I wherein Y is sulfur: R is a halogenated lower-alkyl, preferably fluorinated loweralkyls such as CF;; and C F R, R and R are hydrogen or lower-alkyl, it being especially preferred that R be hydrogen and R and R lower-alkyl. Especially valuable are N,N-dimethyI-N'-(S-trifluoromethyl- 1,3,4-thiadiazol-2-yl)formamidine and N,N-dimethyl- N '-(5-pentafluoroethyl-1,3,4-thiadiazol- 2-yl)formamidine which are excellent preand postemergent herbicides.

The starting compounds of the formula 11 wherein Y is sulfur can be prepared by reacting the appropriate carboxylic acid with the appropriate thiosemicarbazides, using polyphosphoric acid as a dehydrating agent, as described in pending application Ser. No. 37,836, filed May 15, 1970, of T. Cebalo, et al. Those compounds of formula I] wherein Y is oxygen can be prepared by conventional methods. For example, ring closure of acylated thiosemicarbazides or semicarbazides can be effected using lead oxide, e.g. see US. Pat. No. 2,832,787.

The amides of formula III are available as articles of commerce or can be prepared by conventional and known procedures. For example, they can be prepared by reacting the appropriate acid chloride or carboxylic acid esters with the selected amine.

The novel compounds of this invention and their preparation will be further illustrated by the folllowing examples.

EXAMPLE 1 N,N-Dimethyl-N-(5-trifluoromethyl- 1,3 ,4-thiadiazol-2-yl )formamidine To a stirred solution of dimethylformamide (29.2 ml,

27.4 g, 0.230 mole) in dry benzene (50 ml) is added, dropwise, with water bath cooling, a solution of phosphorus oxychloride (13.2 ml, 23.1 g, 0.151 mole) in dry benzene (50 ml). The mixture is allowed to stand the filtrate by evaporation and filtration. The total yield of N,N-dimethyl- N'-(5-trifluoromethy1-1 ,3 ,4-thiadiazol-2- yl)formamidine is 5.52 g (0.246 mole, 91.5 percent; overall yield 81.4 percent), m.p. 64-65.

Employing the method substantially as describedin Example 1, but substituting for the thiadiazole and formamide reactants employed therein equivalent quantities of the 2-amino-5-R-l,3,4-thiadiazoles and.

the l I,N-RR substituted formamides described in Table I, there are produced the N,N-R ,R -N'-(5-R-,

1,3,4-thiadiazol-2-yl)formamidines, also described in Table 1, according to the reaction scheme illustrate therein.

TABLE I R c c NH H c N PO C13 I l 2 2 R-C C-N=C EXAMPLE R R R- M.P Elemental Analyses Calculated Found C H N C H N 2 CH CH, CH, 81-3 42.39 5.93 32.96 42.12 519 32.79 3 C F, CH CH 51-4" 30.65 2.58 20.43. 31.21 2.65 21.05 4 CHF CH CH 74-8 34.98 3.93 27.20 34.99 3.85 26.97 5 ClF C CH; CH 937 29.94 2.93 23.28 30.27 2.70 23.54 6 (CHQ C CH CH 84-6" 50.91 7.60 26.39 49.55 7.46 26.54

Another conventional method which can be employed to prepare the novel amidines of this invention is the reaction of the amine of formula ll with an amide acetal in accordance with the following reaction sewherein R, R, R, R and Y are as previously defined and R is lower-alkyl, preferably methyl. This method is preferred as an alternate synthesis in cases where the amide (111) does not easily react with the amine (II). For example, when R in formula I is methyl, it has been found that the appropriate amide acetal must be employed. The following example illustrates a reaction carried out with a preferred amide acetal of this invention.

EXAMPLE 7 C H N Calculated: 35.29 3.50 23.5l Found: 35.59 3.89 22.77

As stated above, the compounds of this invention have utility as herbicides. The specific herbicidal application for which a particular compound of this invention is useful depends upon its phytotoxic properties and its selectivity. Various of them can be utilized as herbicides in typical preemergence and/or posternergence application to vegetation to be controlled. Others can be applied to weeds or crops for defoliation or desiccation. Selected compounds can be utilized to achieve vegetation control for a relatively short period of time, or for total herbicidal applications at higher concentrations. The compounds can be used in various states of purity ranging, for example, from crystals to a technical crude grade. Suitable solvents for these compounds include alcohols, aqueous alcohol solutions and ketones including acetone and methyl isobutyl ketone.

When utilized for herbicidal purposes, compounds of the invention can be formulated in a variety of ways and concentrations for application to the locus for desired vegetation control. It is recognized that the particular type of concentration of formulation, as well as the mode of application of the active ingredient, can govern its biological activity in a given application.

Compounds of the invention can be prepared as simple solutions of the active ingredient in an appropriate solvent in which it is completely soluble at the desired concentration. Such solvent systems include water, alcohols, acetone, aqueous alcohol and acetone, and other organic solvents. These simple solutions can be further modified by the addition of various surfactants, emulsifying or dispersing agents, colorants, odorants, anti-foaming agents, other herbicides or herbidical oils which supplement or synergize the activity of the herbicides of the invention, or other adjuvants for any given application where deemed desirable to impart a particular type of degree of plant responses.

Compounds of the invention can also be formulated in various other types of formulations commonly recognized by those skilled in the art of agricultural or industrial chemicals. These formulations include, for example, compositions containing the active ingredient as granules of relatively large particle size, as powder dusts, as wettable powders, as emulsifiable concentrations, or as a constituent part of any known type of formulation commonly utilized by those skilled in the art. Such formulations include the adjuvants and carriers normally employed for facilitating the dispersion of active ingredient for agricultural and industrial applications of phytotoxicants. These formulations can contain as little as 0.25 percent or more than 95 percent by weight of the active ingredient.

Dust formulations are prepared by mixing the active ingredient with finely divided solids which act as dispersants and carriers for the phytotoxicant in applying it to the locus of application for vegetation control. Typical solids which may be utilized in preparing dust formulations of the active ingredients of the invention include talc, kieselguhr, finely divided clay, fullers earth, or other common organic or inorganic solids. Solids utilized in preparing dust formulations of the active ingredient normally have a particle size of 50 microns or less. The active ingredient of these dust formulations is present commonly from as little as 0.25 percent to as much as 30 percent or more by weight of the composition.

Granular formulations of the active ingredients are prepared by impregnating or adsorbing the toxicant on or into relatively coarse particles of inert solids such as sand, attapulgite clay, gypsum, corn cobs or other inorganic or organic solids. The active ingredient of these granular formulations is commonly present from 1.0 percent to as much as 20.0 percent or more by weight of the composition.

wettable powder formulations are solid compositions of matter wherein the active ingredient is absorbed or adsorbed in or on a sorptive carrier such as finely divided clay, talc, gypsum, lime, wood flour, fullers earth, kieselguhr, or the like. These formulations preferably are made to contain 50 to percent of active ingredient. These wettable powder formulations commonly contain a small amount of a wetting, dispersing or emulsifying agent to facilitate dispersion in water or other liquid carrier utilized to distribute the phytotoxicant to the locus of desired vegetation control.

Emulsifiable concentrate formulations are homogeneous liquid or paste compositions containing the active ingredient which will disperse in water or other liquid carrier to facilitate application of the phytotoxicant to the locus of desired vegetation control. Such emulsifiable concentrate formulations of the active ingredients can contain only the active ingredient with a liquid or solid emulsifying agent or may contain other relatively nonvolatile organic solvents such as isophorone,

dioxane, heavy aromatic naphthas, xylene, or dimethyl l Candidate compounds are dissolved in acetone soluformamide. The active ingredient in such formulations tion in suitable concentrations to achieve the dose/acre commonly comprises 10.0 to 70.0 percent by weight of indicated in Tables II and III upon spray application at the phytotoxicant composition, a rate of 40 gals/acre and 30 pounds pressure. Preemergence and post-emergence treatments are re- EXAMPLE 8 moved to the greenhouse and held for observation.

Tables II and III set forth the results obtained with. OBSERVATIONS various amidines of this invention, when tested for her preiemergence i liost'emergenci: treatmen'ts. are bicidal activity in accordance with the following test oberved dally for mtenm response final obserydtlons procedure. 7 being madefourteen days after treatment. Final responses are indicated 1n Tables II and III asan Herbi- PRE'EMERGENCE cidal Numerical Injury Rating:

Six crop plant and six weed species are seeded in in-' O-no visible effect; 1, 2, 3-slight injury, plant usually dividual disposable 4 inch square containers, watered recovered with little or no reduction in top growth; 4, only in amounts adequate to moisten soil and held for 5, 6-moderate injury, plants usually recovered, but with twenty-four hours before treatment. The crop plants reduced top growth;7, 8, 9-severeinjury,plants usually used are sugar beets (subt), corn, oats, clover (clvr), did not recover; IO-all plants killed. soybeans (soyb), and cotton (cotn). The weeds em- Observations include all abnormal physiological reployed are mustard (mstd), yellow foxtail (ylfx), barnsponses of stem bending, petiole curvature, epinasty, yard grass (bngs), crab grass (cbgs), buckwheat hyponasty, retardation, stimulation root development, (bkwt), and morning glory (mngy). necrosis and related growth regulant characteristics. In

The foregoing crop plant and weed species are Table II and III abbreviations for the observed plant inseeded by growth-time requirement schedules in indijury and response are as follows: burn (B), chlorosis vidual disposable 4 inch square containers, watered as (Cl), normal (N), necrosis (Ne), no response (0), rerequired, and maintained under greenhouse conditions. 1S tarded or reduced (R), tip (Ti).

TABLE II Ball LN- Pre Emergence Herhicidal Evaluation When all crop plants and weeds have reached suitable growth development, generally first true leaf stage, plants and weeds appropriate to pertaining test requirements are selected for uniformity of growth anddevelopment. One 4 inch container of each plant and weed, averaging 6 (corn) to (crabgrass) or more plants or weeds per individual container, is then treated. Six crop and six weed containers are used in each evaluation.

FORMULATION AND TREATMENT 3 dan n Injury Rating: Physiological Response DOSE I R R' R R LBS/A UBT CORN OATS CLVR SOYB COTN MSTD YLFX BNGS CBGS BKWT MNGY' CF CH CH, H 10 lO:Ne ScNe l0zNe lO:Ne l0:Ne lOzNe 9:Ne 8:Ne lOzNe lOzNe l0:Ne

()zNe 4 ltNe lzNe I 7:Ne 0:0 0:0 41Ne 7:Ne 5:Ne S:Ne 8:Ne 0:0

099:Nc 2 0:0 0:0 9:Ne 0:0 0:0 7:Ne 3:Ne 4:Ne 4:Ne 7:Ne 0.0 ()98:Ne 1 0:0 0:0 8:Ne 0:0 0:0 SzNe 3:Ne 32Ne- 3:Ne 7:Ne 0:0

094:Ne CF CH CH, (HCIH l0 N lzNe 22RNe 9:RNe 9zRNe 9zRNe l0:Ne 6:RNe 8zRNe )zRNe l0:RNe 8:Ne

0: e I C F CH;, CH, H l0 I0:Ne ZzNe I0:Ne l0:Ne l0:Ne l0:Ne l0:Ne l0:Ne lOzNe I0:Ne 10:Ne

()zNe 4 4:RNe 2:RNe lOzNc 92Ne l0zNe I():Ne 92Ne lOzNe lOzNe l0:Ne 8:RNe

0:Ne 2 IR l:RNe 9:Ne 9:Ne 9:Ne l0zNe 8:Ne l0:Ne 9:Ne lOzNe 0:0 OzNe t CH CH CH H II) 0:0 0:0 0:0 0:0 0:0 0:0 0:0 0:0 0:0 0:0 0:0 0:0 CH CH H 4 [:Cl 0:0 0:0 7:RNe l:Cl 0:0 lzRNe 0:0 0:0 0:0 l:Cl 0:0 HF;

N---N R n It R-C C--N=CNR R TABLE IV-Continued EXAMPLE R Y 24 o-methoxyphenyl S y 25 pdimechylmnino )phenyl O 26 p-cyanophenyl M i s 27 ethenyl S 28 i-propenyl 0 t 29 1-hexeny1 3 3O trichloromethyl s 31 trichloromethyl O 32 tribromozncthyl s 33 trifluoromethyl 0 31', fluoro S 35 chloro S 3 brorllo s t 37 methoxy 3b butoaty O The examplesset forth in Table V demohstrate other 35 TABLE VC0ntinued novel acetamldmes of this invention. Employing the v procedure of Example 7, but substituting for the thiadi- EXAMPLE R Y azole and acetamlde acetal reactants, equivalent quan- 46 C255 methyl methyl 0 I titles of the appropriate 2-am1no-5-R-l,3,4- 47 difluoromethyl methyl methyl S thiadiazoles, or 2-amino-5-R-l,3,4-oxadiazoles, and dlflumqmethyl methyl methyl 0 1 2 49 chlorodlfluoromethyl methyl methyl S the N ,N-R ,R -substltuted acetamlde dlmethyl acetals 50 h| difl h l th l methyl 0 described in Table V, there are produced the corre- E g): fiy: g 2 tuty met y met spondlng I I N,NR,R -N'-(5-Rl),3,4th12ldlflZOl 53 H ethyl ethyly s 2-yl)acetamldmes, or N,N-R,R--N'-(5-R-l,3,4- 54 H ethyl methyl 0 v oxadiazol-2-yl)acetomidines also described in Table V, 55 y P s 56 trlfluoromethyl ethyl ethyl S according to the reaction scheme set forth in Table V. 57 trifluoromethyl hm l n-propyl 'S 5 8 trifl uoromethyl nbutyl n-butyl S TABLE V 59 trifluoromethyl n-hexyl n-hexyl S 60 tril'luoromethyl methyl ethyl S f 6 I tritluoromethyl methyl methyl 0 h 1 62 trifluoromethyl eth l ethyl ,0 5) l. /R 63 c n, ethyl ethyl s t CH -CN 64 (3 F; ethyl ethyl 0 t, R C 2 3 I g 65 C F n hexyl n-hexyl s a t OCF 66 cyclohexyl methyl methyl S t 3 67 phcnyl methyl methyl 0' 68 p-bromophenyl methyl methyl S t 6) trihromomethyl methyl methyl 0 N N CH3 1 70 fluoro n-propyl methyl S ll 11 L /R 7 l ethoxy methyl methyl O R-C C-N=o-il Further illustrative of the novel amidines of this in-@ EXAMPLE R t 2 Y vention are those set forth in Table VI. These compounds are produced by substituting for the thiadiazole 39 H methyl methyl 5 and formamide reactants of Example 1, or thiadiazole 40 H methyl methyl 0 l f E l 7 l 41 methyl methyl methyl 5 and amide aceta reactants o xamp e equlva ent meth l methyl methyl 0 quantities of the appropriate 2-8mll'10-5R-1,3,4- {32332123} $2331: 232;} g thiadiazole or Z-amino-S-R-l,3,4 oxadiazole with the 45 GE, methyl meth l 5 suitable amide or amide acetaL EXAMPLE R Y R R 3 CH -CH=C 10 CF3 s 011 3 CH2 H2 106 cF s CH 5 CH3 @-ca 107 cr s CHgCl H H 108 P3 s H [s CF 3 CH cit H 11o CF3 s -ch ca -CH2-CH2 *R and R linked together through nitrogen of the amidine moiety.

We claim:

1. An herbicidal composition comprising an inert carrier and an effective amount of a compound having the following formula 3 N N R 1 l l l R C C-N:

methyl, R and R' are methyl and R" is hydrogen.

5. The composition of claim 1 wherein R is C- F R and R are methyl and R is hydrogen.

6. The composition of claim 1 wherein R is difluoromethyl, R and R are methyl and R is hydrogen.

7. The composition of claim 1 wherein R is trifluoroethyl, and R, R and R are methyl.

8. The composition of claim 1 wherein R is ClF C, R and R are methyl, and R" is hydrogen.

9. The composition of claim 1 wherein R is t-butyl, R and R are methyl and R is hydrogen.

10. A method for controlling weeds which comprises applying to the locus to be treated a phytotoxic amount of a composition comprising a compound of the formula wherein Y represents sulfur, R represents lower alkyl I or halogenated lower alkyl and each of R"; R and R independently represents hydrogen or lower alkyl.

11. The method of claim .10 where further in said" composition R is selected from CF C F CHF- ClF C, methyl and t-butyl.

12. The method of claim 10 where further in said composition R, R, R are methyl and R is hydrogen 13. The method of claim 10 where further in said composition R is C F R and R are methyl andR is hydrogen.

16..The method of claim 10 where further in said I composition R is difluoromethyl, R and R are methyl and R is hydrogen.

17. The method of claim 10 where further in said composition R is trifiuoromethyl. and R R and R are,

methyl.

18. The method of claim 10 where further in said composition R is ClF C, R and R are methyl, and

is hydrogen. g

19. The methodof claim 10 where further in said composition R is t-butyl, R and R are methyl and R is hydrogen.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3, 74 74 DATED April 1, 1975 INVENTOWS) I Tony Cebalo and Robert Edward Buntrock It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 53, "of up to 6 carbons" should read-of up to 6 carbon--- Column 6, lines 25 and 26, 'emulsifiable concentrations" should read---emulsifiable concentrates--- in Table II, the first six columns should read as follows- DOSE R R R R LBS/A SUBT CF3 CH3 CH3 H 1O 10 :Ne

Z 8:Ne

l rzNe CF CH CH3 (HCl) H 10 lOzNe C2F CH3 CH3 H 10 lO:Ne

1 lOZNE CH CH CH3 H 10 o 0 CHF CH CH3 H 4 lzCl UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION P ATE NT NO. 1 3,874, 874

DATED I April 1, 1975 Page 2 Tony Cebalo and Robert Edward Buntrock INVENTOR(S) I It is certified that error appears in the abOVe identified patent and that said Letters Patent are hereby corrected as shown beiow: (c i d) In Table III, the first six columns should read as follows----- R R R2 R 233% SUBT CF3 CH3 CH3 H 5 10 l ZzNe CF3 CH3 CH (HCl) H 3 5 8:Ne 0 15 I CH3 CH3 H 5 lOzNe 2 4 Ne l izNe CH3 CH3 CH3 H 5 lzNe CHFZ CH3 CH3 H 2 0=0 Column 11, line 46, "oxadiazol-Z-yl)acetomidines" should read oxadiazol-Z-yl)acetamidines--- Signed and Scaled this eighteenth Day Of November 1975 [SEAL] A ttes r:

RUTH C. MASON C. MARSHALL DANN :HH'MIHX ()jji'vv ('ummixsmnur nl'lurr'nls and Trademarks 

1. AN HERBICIDAL COMPOSITION COMPRISING AN INERT CARRIER AND AN EFFECTIVE AMOUNT OF A COMPOUND HAVING THE FOLLOWING FORMULA
 2. The composition of claim 1 where R is selected from CF3, C2F5, CHF2, ClF2C, methyl and t-butyl.
 3. The composition of claim 1 wherein R, R1, R2 are methyl and R3 is hydrogen.
 4. The composition of claim 1 wherein R is trifluoromethyl, R1 and R2 are methyl and R3 is hydrogen.
 5. The composition of claim 1 wherein R is C2F5, R1 and R2 are methyl and R3 is hydrogen.
 6. The composition of claim 1 wherein R is difluoromethyl, R1 and R2 are methyl and R3 is hydrogen.
 7. The composition of claim 1 wherein R is trifluoroethyl, and R1, R2 and R3 are methyl.
 8. The composition of claim 1 wherein R is ClF2C, R1 and R2 are methyl, and R3 is hydrogen.
 9. The composition of claim 1 wherein R is t-butyl, R1 and R2 are methyl and R3 is hydrogen.
 10. A method for controlling weeds which comprises applying to the locus to be treated a phytotoxic amount of a composition comprising a compound of the formula
 11. The method of claim 10 where further in said composition R is selected from CF3, C2F5, CHF2, ClF2C, methyl and t-butyl.
 12. The method of claim 10 where further in said composition R, R1, R2 are methyl aNd R3 is hydrogen.
 13. The method of claim 10 where further in said composition R is trifluoromethyl, R1 and R2 are methyl and R3 is hydrogen.
 14. The method of claim 10 where further in said composition R is trifluoromethyl, R1 is methyl, R2 is methyl .HCl, and R3 is hydrogen.
 15. The method of claim 10 where further in said composition R is C2F5, R1 and R2 are methyl and R3 is hydrogen.
 16. The method of claim 10 where further in said composition R is difluoromethyl, R1 and R2 are methyl and R3 is hydrogen.
 17. The method of claim 10 where further in said composition R is trifluoromethyl, and R1 , R2 and R3 are methyl.
 18. The method of claim 10 where further in said composition R is ClF2C, R1 and R2 are methyl, and R3 is hydrogen.
 19. The method of claim 10 where further in said composition R is t-butyl, R1 and R2 are methyl and R3 is hydrogen. 